Instantaneous water heater

ABSTRACT

There is provided an instantaneous water heater capable of expelling heated water or steam when internal pressure reaches or exceeds a predetermined pressure, thus preventing an accident, product damage, or the like. The instantaneous water heater includes a main body having an inlet allowing water to be introduced therethrough and an outlet allowing water to be discharged therethrough; a heating unit disposed in the main body and heating water introduced to the main body; and a decompression unit connected to a decompression hole disposed in the main body and expelling heated water or steam to the outside thereof when internal pressure within the main body reaches or exceeds a predetermined pressure.

PRIORITY

This application claims the priority under 35 U.S.C. §119(a) to Korean Patent Application No. 10-2012-0038743 filed on Apr. 13, 2012 and Korean Patent Application No. 10-2012-0150105 filed on Dec. 20, 2012 in the Korean Intellectual Property Office, the entire content of each of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an instantaneous water heater for heating water introduced thereto to a predetermined temperature within a relatively short time and expelling it to the outside thereof, and more particularly, to an instantaneous water heater for expelling heated water or steam to the outside thereof when internal pressure is higher than a predetermined pressure, to thus maintain the internal pressure at a level less than the predetermined pressure, thus preventing an accident causing damage to a product.

2. Description of the Related Art

An instantaneous water heater is an apparatus for rapidly heating water introduced thereto to a predetermined temperature within a relatively short time and expelling the same to provide heated water, i.e., hot water, to a user. The instantaneous water heater may be provided, for example, in a direct-type water purifier or a tank-type water purifier. The direct-type water purifier is configured to enable water to flow by existing water pressure, and thus, it does not have a storage tank for storing water filtered by a water purifying filter. The tank-type water purifier is configured to pressurize water with a pump, or the like, so as to flow, and thus, it includes a water storage tank storing water filtered by a water purifying filter.

The related art instantaneous water heater only includes an inlet and an outlet. Thus, if the outlet of the instantaneous water heater, provided to allow heated water, i.e., hot water, to be discharged therethrough is clogged, or a valve provided in a connection pipe connected to the outlet does not operate, water within the instantaneous water heater cannot be expelled to the outside thereof and remain therein.

With water remaining in the instantaneous water heater, if a heating unit of the instantaneous water heater is driven, water within the instantaneous water heater is continuously heated and may be overheated to thus increase internal pressure in the instantaneous water heater. When internal pressure of the instantaneous water heater reaches or exceeds a predetermined pressure, the instantaneous water heater may be damaged or may even explode due to the high internal pressure. Also, damage to the instantaneous water heater may cause an accident in which a user is injured by being burned or electrically shocked.

SUMMARY OF THE INVENTION

The present invention has been devised upon recognition of the issues and problems evident in the related art instantaneous water heater.

An aspect of the present invention provides an instantaneous water heater capable of expelling heated water or steam to the outside thereof when internal pressure reaches or exceeds a predetermined pressure.

Another aspect of the present invention provides an instantaneous water heater in which internal pressure is maintained at a level lower than a predetermined pressure.

An aspect of the present invention provides an instantaneous water heater capable of preventing an occurrence of an accident, product damage, or the like, due to an increase in internal pressure.

An instantaneous water heater in relation to an embodiment for realizing at least one of the tasks may have the following features.

The present invention is based on a technique in which, when internal pressure reaches or exceeds a predetermined pressure, heated water or steam is expelled, thus maintaining the internal pressure at a level below the predetermined pressure.

According to an aspect of the present invention, there is provided an instantaneous water heater including a main body having an inlet allowing water to be introduced therethrough and an outlet allowing water to be discharged therethrough; a heating unit disposed in the main body and heating water introduced to the main body; and a decompression unit connected to a decompression hole disposed in the main body and expelling heated water or steam to the outside thereof when internal pressure within the main body reaches or exceeds a predetermined pressure.

The decompression unit may include a safety valve having one side connected to the decompression hole and opened when the internal pressure within the main body is equal to or higher than the predetermined pressure.

The decompression hole may be formed in an upper portion of the main body.

The decompression hole may be formed in a portion of the main body in which the outlet is disposed.

The outlet and the decompression unit may be disposed in the upper portion of the main body.

The decompression unit may further include a drain pipe connected to the other side of the safety valve.

The instantaneous water heater may further include a controller connected to the decompression unit and informing a user about an operation of the decompression unit when the decompression unit operates.

The controller may be connected to an alarm unit and operate the alarm unit when the decompression unit operates.

The controller may be connected to the heating unit, and when the decompression unit operates, the controller may stop the operation of the heating unit.

The main body may be provided in a direct-type water purifier or a tank-type water purifier, and when the decompression unit operates, the controller may turn off power supplied to the direct-type water purifier or the tank-type water purifier.

The main body may include a first main body formation member and a second main body formation member coupled to the first main body formation member, and the inlet or the outlet may be provided in any one of the first main body formation member and the second main body formation member.

The instantaneous water heater may further include a flow unit provided in the main body and including a flow channel connected to the inlet and the outlet such that introduced water is heated by the heating unit while flowing therein for a predetermined period of time.

The flow unit may include a rim member forming the edge of the flow channel.

The flow unit may further include one or more flow channel formation members connected to the rim member to form a flow channel.

The heating unit may be installed on an outer surface of the main body.

The heating unit may include a surface-type heater.

The surface-type heater may be a ruthenox heater.

The safety valve may be connected to a flow sensor, and when leakage from the safety valve is sensed by the flow sensor, the controller connected to the safety valve and the flow sensor may interrupt introduction of water to the inlet and inform a user accordingly.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of an instantaneous water heater according to an embodiment of the present invention;

FIG. 2 is an exploded perspective view of the instantaneous water heater of FIG. 1 according to an embodiment of the present invention;

FIG. 3 is an exploded perspective view of the instantaneous water heater according to another embodiment of the present invention;

FIG. 4 is an exploded perspective view of the instantaneous water heater according to another embodiment of the present invention; and

FIG. 5 is a perspective view illustrating an operation of the instantaneous water heater of FIG. 1 according to an embodiment of the present invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION

To help understand the foregoing features of the present invention, an instantaneous water heater in relation to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, embodiments most appropriate to help in an understanding of the technical features of the present invention will be described, the technical features of the present invention are not limited by the described embodiments and merely illustrate the implementation of the present invention through the embodiments described hereinafter. Thus, the present invention can be variably modified within the scope of the present invention through the embodiments described below, and such modifications are within the scope of the present invention. In order to help understand the embodiments described hereinafter, like or similar reference numerals are used for relevant components among the components having the same function in the respective embodiments in the accompanying drawings.

Embodiments in relation to the present invention are based on a technique that when internal pressure reaches or exceeds a predetermined pressure, heated water or steam is expelled, thus maintaining internal pressure less than the predetermined pressure.

As shown in an embodiment illustrated in FIGS. 1 through 4, an instantaneous water heater 100 according to an embodiment of the present invention may include a main body 200, a heating unit 300, and a decompression unit 400.

As shown in the embodiment illustrated in FIGS. 1 through 4, the main body 200 may have an inlet 200 a and an outlet 200 b. As illustrated in FIG. 5, water may be introduced to the inlet 200 a. To this end, the inlet 200 a may be connected to a water source (not shown) by a connection pipe (not shown). Accordingly, water from the water source may be introduced to the main body 200 through the connection pipe and the inlet 200 a as illustrated in FIG. 5.

When the instantaneous water heater 100 is provided in a direct-type water purifier or a tank-type water purifier (not shown), the water source connected to the inlet 200 a by the connection pipe may be a filtering unit (not shown) which includes one or more water purifying filters filtering water and is provided in the direct-type water purifier or the tank-type water purifier. However, the water source is not limited to the filtering unit of the direct-type water purifier as mentioned above and any water source may be employed as long as it is connected to the inlet 200 a by a connection pipe to provide water to the main body 200.

As described above and as illustrated in FIG. 5, water heated by the heater 300 (to be described later) after being introduced through the inlet 200 a, i.e., hot water, may flow out through the outlet 200 b. As described above, when the instantaneous water heater 100 is provided in a direct-type water purifier or a tank-type water purifier, the outlet 200 b may be connected to a water discharge member (not shown) such as a faucet, or the like, by a connection pipe. Accordingly, heated water, i.e., hot water, flowing out through the outlet 200 b may be discharged to the outside thereof through the water discharge member such as a faucet, or the like, so as to be supplied to a user.

As shown in the embodiment illustrated in FIGS. 1 through 4, the inlet 200 a may be disposed in a lower portion of the main body 200. Also, the outlet 200 b may be disposed in an upper portion of the main body 200. Thus, water from the water source may be introduced to the lower portion of the main body 200 through the inlet 200 a and rise upwardly from the lower portion of the main body 200. When water is heated by the heating unit 300 (to be described later), namely, when water is turned into hot water, the hot water may be expelled from the upper portion of the main body 200 through the outlet 200 b. Through such a configuration, water present in the upper portion of the main body 200 having a relatively high temperature may be expelled from the outlet 200 b and provided to the user.

However, the positions of the inlet 200 a and the outlet 200 b in the main body 200 are not limited to those in the embodiment illustrated in FIGS. 1 through 4, and the inlet 200 a and the outlet 200 b may be placed in any positions in the main body 200, as long as water can be introduced from a water source such as a filtering unit, or the like, of the foregoing direct-type water purifier or the tank-type water purifier and water heated by the heating unit 300 (to be described), i.e., hot water, can be expelled to the foregoing water discharge member such as a faucet, or the like, so as to be supplied to the user.

As shown in the embodiment illustrated in FIGS. 1 through 4, the main body 200 may include a first main body formation member 210 and a second main body formation member 220 coupled to the first main body formation member 210. In this case, both the inlet 200 a and the outlet 200 b may be provided in the first main body formation member 210 as shown in the illustrated embodiment.

However, the inlet 200 a may be provided in the first main body formation member 210, and the outlet 20 b may be provided in the second main body formation member 220. Also, the inlet 200 a may be provided in the second main body formation member 220, and the outlet 20 b may be provided in the first main body formation member 210. Also, both the inlet 200 a and the outlet 200 b may be provided in the second main body formation member 220. Namely, the inlet 220 a or the outlet 220 b may be provided in at least any one of the first main body formation member 210 and the second main body formation member 220.

As shown in the embodiment illustrated in FIGS. 1 through 4, the heating unit 300 may be disposed in the main body 200. Referring to FIG. 5, the heating unit 300 may be configured to heat water introduced to the main body 200 through the inlet 200 a as mentioned above.

To this end, as shown in the embodiment illustrated in FIGS. 1 through 4, the heating unit 300 may be installed on an outer surface of the main body 200. Also, as shown in the illustrated embodiment, the heating unit 300 may include a surface-type heater (or a surface heater). Thus, heating efficiency of the instantaneous water heater 100 can be improved and the size of the instantaneous water heater 100 can be reduced.

The heating unit 300 as a surface-type heater may be connected to an electricity source (not shown). When electricity is supplied to operate the heating unit 300 as a surface-type heater, as mentioned above and as illustrated in FIG. 5, water introduced to the main body 200 through the inlet 300 a may be heated into hot water.

The surface-type heater included in the heating unit 300 may be a ruthenox heater. However, the surface-type heater included in the heating unit 300 is not limited to the ruthenox heater and any known surface-type heater may be employed as long as it is a surface-type heater. Also, the heating unit may be configured by a means other than the surface-type heater.

As shown in the embodiment illustrated in FIGS. 1 through 4, when the main body 200 includes the first main body formation member 210 and the second main body formation member 220, the heating unit 300 may include a first heating unit 310 provided in the first main body formation member 210 and a second heating unit 320 provided in the second main body formation member 220. However, the configuration of the heating unit 300 provided in the main body 200 is not limited thereto and any known configuration may be employed as long as it is provided in the main body 200 to heat water introduced to the main body 200.

As shown in the embodiment illustrated in FIGS. 1 through 4, the decompression unit 400 may be connected to a decompression hole 200 c provided in the main body 200. The decompression unit 400 may be configured to expel water or steam when internal pressure within the main body 200 reaches a predetermined pressure, e.g., 15 psi or higher. Thus, when internal pressure within the main body 200 reaches or exceeds a predetermined pressure as water within the main body 200 is overheated, heated water or steam within the main body 200 may be expelled to the outside thereof. Thus, the internal pressure within the main body 200 may be maintained, for example, below 15 psi as mentioned above.

Through such a configuration, since the internal pressure within the main body 200 does not exceed the predetermined pressure, the instantaneous water heater 100 including the main body 100 is free from an accident, product damage, or the like. Also, as mentioned above, an accident, product damage, or the like, of a direct-type water purifier, a tank-type water purifier, or the like, including the instantaneous water heater 100 can be prevented.

The internal pressure within the main body 200 may be increased to above the predetermined pressure when the valve (not shown) provided in the connection pipe connected to the outlet 200 b does not operate or when water remains in the main body 200 because the outlet 200 b is clogged, or the like. In this case, since water within the main body 200 cannot be discharged to the outside thereof, even though it is continuously heated by the heating unit 300, as described hereinafter, the water within the main body 200 is overheated and the internal pressure within the main body 200 may be increased to above the predetermined pressure.

Besides, when a temperature is not properly regulated by the heating unit 300 as described hereinafter, water within the main body 200 is overheated and the internal pressure within the main body 200 may be increased to above the predetermined pressure.

To this end, as shown in the embodiment illustrated in FIGS. 1 through 4, the decompression unit 400 may include a safety valve 410. One side of the safety valve 410 may be connected to the decompression hole 200 c as shown in the illustrated embodiment. The safety valve 410 may be configured to be opened when the internal pressure within the main body 200 exceeds the predetermined pressure. Thus, when the internal pressure within the main body 200 is above the predetermined pressure, the safety valve 410 may be opened and heated water or steam within the main body 200 may be expelled to the outside thereof. Accordingly, the internal pressure within the main body 200 may be maintained at a level below the predetermined pressure.

The configuration of the safety valve 410 is not particularly limited. Namely, the safety valve 410 may have any known configuration as long as it is opened when the internal pressure within the main body 200 reaches or exceeds the predetermined pressure or closed when the level of the internal pressure within the main body 200 is below the predetermined pressure. For example, the safety valve 410 may be an electronic safety valve or a mechanical safety valve. Also, an electronic safety valve and a mechanical safety valve may be used together as the safety valve 410.

When the safety valve 410 is an electronic safety valve, the safety valve 410 may be integrally configured with a pressure sensor (not shown) measuring internal pressure within the main body 200 or may be electrically connected to the pressure sensor. Also, an opening and closing member (not shown) opening and closing a flow channel (not shown) formed in the safety valve 410 may be movably provided in the safety valve 410. The opening and closing member may be associated with, for example, a solenoid (not shown) so as to be moved by an input electrical signal.

Through such a configuration, when the pressure sensor senses that internal pressure within the main body 200 is equal to or higher than the predetermined pressure, the pressure sensor transmits an electrical signal to the safety valve 410 to open the safety valve 410. Namely, the opening and closing member may be moved to a position in which it opens the flow channel. When the pressure sensor senses that the internal pressure within the main body 200 is lower than the predetermined pressure, the pressure sensor may transmit an electrical signal to the safety valve 410 to close the safety valve 410. Namely, the opening and closing member may be moved to a position in which it closes the flow channel.

Also, when the safety valve 410 is a mechanical safety valve, an opening and closing member opening and closing the flow channel formed in the safety valve 410 may be movably provided in the safety valve 410, and the opening and closing member may be supported by an elastic member (not shown). Through such a configuration, when internal pressure within the main body 200 is equal to or higher than the predetermined pressure, the opening and closing member may overcome elastic force of the elastic member and move to a position in which it opens the flow channel by force acting on the opening and closing member based on the internal pressure within the main body 200. When the internal pressure within the main body 200 is reduced to be lower than the predetermined pressure, the opening and closing member may be moved to a position in which it closes the flow channel by elastic force of the elastic member.

When a mechanical safety valve is used as the safety valve 410, although a problem in relation to an electronic system arises, the safety valve 410 may not operate. Namely, even when an electronic system other than the heating unit 300 has a fault so the internal pressure within the main body 200 exceeds the predetermined pressure, heated water or steam within the main body 200 may not be expelled to the outside thereof.

Meanwhile, as shown in the embodiment illustrated in FIGS. 1 through 4, the decompression hole 200 c may be provided in an upper portion of the main body 200. In the case that the decompression hole 200 c is provided in an upper portion of the main body 200, as mentioned above, when the safety valve 410 is opened, steam, having a specific gravity lower than that of water, collected to the upper portion of the main body 200 may be first expelled to the outside thereof through the safety valve 410. Also, when the decompression hole 200 c is provided in the upper portion of the main body 200, since steam closely related to an increase in the internal pressure within the main body 200 is first expelled, the internal pressure within the main body 200 may be relatively quickly reduced, improving a decompression effect.

Also, the decompression hole 200 c may be provided in a portion of the main body 200 in which the outlet 200 b is disposed. For example, as shown in the embodiment illustrated in FIGS. 1 through 4, both the outlet 200 b and the decompression hole 200 c may be disposed in the upper portion of the main body 200.

Heated water or steam having a relatively high temperature is present in the portion of the main body 200 in which the outlet 200 b is disposed. Thus, when internal pressure within the main body 200 reaches or exceeds the predetermined pressure so heated water or steam is expelled to the outside thereof by the safety valve 410 connected to the decompression hole 200 c, heated water or steam having a relatively high temperature may be expelled to the outside thereof. Thus, the internal pressure within the main body 200 can be relatively quickly reduced, improving the decompression effect.

However, the position of the decompression hole 200 c in the main body 200 is not limited to the position in the embodiment illustrated in FIGS. 1 through 4, and the decompression hole 200 c may be placed in any position as long as the safety valve 410 is connected thereto and opened to expel heated water or steam from the main body 200 when the internal pressure within the main body reaches the predetermined pressure.

As shown in the embodiment illustrated in FIGS. 1 through 4, the decompression unit 400 may further include a drain pipe 420. The drain pipe 420 may be connected to the other side of the safety valve 410 as shown in the illustrated embodiment. Thus, as illustrated in FIG. 5, when the internal pressure within the main body 200 reaches or exceeds the predetermined pressure so the safety valve 410 is opened, heated water or steam within the main body 200 may be expelled to the outside thereof through the drain pipe 420. Thus, heated water or steam may be guided through the drain pipe 420 so as to be expelled without scattering. Thus, a safety accident, such as the user being burned or the device being damaged, or the like, which may occur when heated water or steam is expelled to the outside in a scattering manner, can be prevented.

The instantaneous water heater 100 according to an embodiment of the present invention may further include a controller (not shown). The controller may be connected to the decompression unit 400. Namely, as shown in the embodiment illustrated in FIGS. 1 through 4, the controller may be electrically connected to the safety valve 410. When the decompression unit 400 operates, the controller may inform the user accordingly. Namely, when the internal pressure within the main body 200 reaches or exceeds the predetermined pressure so the safety valve 410 is opened and heated water or steam within the main body 200 is expelled to the outside thereof, the controller may provide corresponding information to the user.

To this end, the controller may be connected to an alarm unit (not shown). When the decompression unit 400 operates, the controller may operate the alarm unit to provide the foregoing pertinent information to the user. Namely, as mentioned above, when the internal pressure within the main body 200 reaches or exceeds the predetermined pressure so the safety valve 410 is opened, the controller may operate the alarm unit to provide the foregoing pertinent information to the user. Accordingly, the user may stop the operation of the heating unit 300 or when the instantaneous water heater 100 according to an embodiment of the present invention is provided in a direct-type water purifier or a tank-type water purifier, the user may take appropriate measures such as stopping the operation of the direct-type water purifier or the tank-type water purifier.

Also, the controller may be connected to the heating unit 300. When the decompression unit 400 operates, the controller may stop operation of the heating unit 300. Namely, as mentioned above, when the internal pressure within the main body 200 reaches or exceeds the predetermined pressure so the safety valve 410 is opened, the controller may stop the operation of the heating unit 300. Thus, the user may recognize that the decompression unit 400 has been operated, namely, the safety valve 410 has been opened. When the operation of the heating unit 300 is stopped, water within the main body 200 is not heated any longer, and thus, the internal pressure within the main body 200 can be relatively quickly decompressed.

As mentioned above, the main body 200 may be provided in a direct-type water purifier or a tank-type water purifier. Here, when the decompression unit 400 operates, the controller may cut off entire power supplied to the direct-type water purifier or a tank-type water purifier. Thus, upon viewing that a display provided in the direct-type water purifier or the tank-type water purifier is turned off, or the like, the user may recognize that all operations are stopped due to a critical accident. Also, since the instantaneous water heater 100 does not operate, the user may take measures such as he or she may request a technician to make repairs and inspection, or the like.

Meanwhile, the safety valve 410 may be connected to a flow sensor (not shown). Damage to or leakage of the safety sensor 410 may be sensed by the flow sensor. Namely, when a flow rate other than a normal state is sensed by the flow sensor, it may be determined that the safety valve 410 has been damaged to leakage.

Also, the controller connected to the safety valve 410 may also be connected to the flow sensor. As mentioned above, when leakage from the safety valve 410 is sensed by the flow sensor, the controller may interrupt introduction of water to the inlet 200 a. For example, the controller may close the valve provided in the connection pipe connected to the inlet 200 a to interrupt introduction of water to the inlet 200 a. Thereafter, the controller may inform the user about the leakage resulting from damage to the safety valve 410. For example, the controller may display corresponding information on a display unit or operates an alarm unit to user recognition.

As shown in the embodiment illustrated in FIGS. 3 and 4, the instantaneous water heater 100 according to an embodiment of the present invention may further include a flow unit 500. The flow unit 500 may be provided in the main body 200. As shown in the illustrated embodiment, when the main body 200 includes the first main body formation member 210 and the second main body formation member 220, the flow unit 500 may be disposed between the first main body formation member 210 and the second main body formation member 220.

As shown in the embodiment illustrated in FIGS. 3 and 4, the flow unit 500 may include a flow channel P formed to be connected to the inlet 200 a and the outlet 200 b. Accordingly, water introduced to the main body 200 through the inlet 200 a may flow in the flow channel P formed in the flow unit 500 and heated by the foregoing heating unit 300.

As shown in the embodiment illustrated in FIGS. 3 and 4, the flow unit 500 may include a rim member 510. The rim member 510 may form the edge of the flow channel P. As shown in the embodiment illustrated in FIG. 3, the flow unit 500 may include only the rim member 510. In this case, the flow unit 500 may include only a single flow channel P. The shape of the rim member 510 is not particularly limited. Namely, the rim member 510 may have any shape as long as it forms the edge of the flow channel P.

As shown in the embodiment illustrated in FIG. 4, the flow unit 500 may further include a flow channel formation member 520. As shown in the illustrated embodiment, one or more flow channel formation members 520 may be connected to the rim member 510 to form the flow channel P. As shown in the illustrated embodiment, a plurality of flow channel formation members 520 may be connected in a crisscross manner to the rim member 510 to form the flow channel P.

However, the configuration in which the flow channel formation member 520 is connected to the rim member 510 to form the flow channel P is not limited to the illustrated embodiment and any configuration may be employed as long as it forms the flow channel P in which water flows.

As described above, in the case of using the instantaneous water heater according to an embodiment of the present invention, when internal pressure reaches or exceeds a predetermined pressure, heated water or steam may be expelled to maintain the internal pressure at a level below the predetermined pressure, and an accident, product damage due to an increase in the internal pressure, or the like, can be prevented.

The instantaneous water heater as described above is not limited in its application of the configurations of the foregoing embodiments, but the entirety or a portion of the embodiments can be selectively combined to be configured to have various modifications. 

What is claimed is:
 1. An instantaneous water heater comprising: a main body having an inlet allowing water to be introduced therethrough and an outlet allowing water to be discharged therethrough; a heating unit disposed in the main body and heating water introduced to the main body; and a decompression unit connected to a decompression hole disposed in the main body and expelling heated water or steam to the outside thereof when internal pressure within the main body reaches or exceeds a predetermined pressure.
 2. The instantaneous water heater of claim 1, wherein the decompression unit includes a safety valve having one side connected to the decompression hole and opened when the internal pressure within the main body is equal to or higher than the predetermined pressure.
 3. The instantaneous water heater of claim 2, wherein the decompression hole is formed in an upper portion of the main body.
 4. The instantaneous water heater of claim 2, wherein the decompression hole is formed in a portion of the main body in which the outlet is disposed.
 5. The instantaneous water heater of claim 4, wherein the outlet and the decompression unit are disposed in the upper portion of the main body.
 6. The instantaneous water heater of claim 2, wherein the decompression unit further includes a drain pipe connected to the other side of the safety valve.
 7. The instantaneous water heater of claim 1, further comprising a controller connected to the decompression unit and informing a user about an operation of the decompression unit when the decompression unit operates.
 8. The instantaneous water heater of claim 7, wherein the controller is connected to an alarm unit and operates the alarm unit when the decompression unit operates.
 9. The instantaneous water heater of claim 7, wherein the controller is connected to the heating unit, and when the decompression unit operates, the controller stops the operation of the heating unit.
 10. The instantaneous water heater of claim 7, wherein the main body is provided in a direct-type water purifier or a tank-type water purifier, and when the decompression unit operates, the controller turns off every power supplied to the direct-type water purifier or the tank-type water purifier.
 11. The instantaneous water heater of claim 1, wherein the main body includes a first main body formation member and a second main body formation member coupled to the first main body formation member, and the inlet or the outlet is provided in any one of the first main body formation member and the second main body formation member.
 12. The instantaneous water heater of claim 1, further comprising a flow unit provided in the main body and including a flow channel connected to the inlet and the outlet such that introduced water is heated by the heating unit while flowing therein for a predetermined period of time.
 13. The instantaneous water heater of claim 12, wherein the flow unit includes a rim member forming the edge of the flow channel.
 14. The instantaneous water heater of claim 13, wherein the flow unit further includes one or more flow channel formation members connected to the rim member to form a flow channel.
 15. The instantaneous water heater of claim 1, wherein the heating unit is installed on an outer surface of the main body.
 16. The instantaneous water heater of claim 15, wherein the heating unit includes a surface-type heater.
 17. The instantaneous water heater of claim 16, wherein the surface-type heater is a ruthenox heater.
 18. The instantaneous water heater of claim 2, wherein the safety valve is connected to a flow sensor, and when leakage from the safety valve is sensed by the flow sensor, the controller connected to the safety valve and the flow sensor interrupts the introduction of water to the inlet and informs a user accordingly. 